What Is a PRD (Product Requirements Document)?

What a PRD is for

A PRD turns a product decision into something a team can build against. It records the problem, the people who have it, what the solution must do and how you will know it worked. Engineers use it to plan and estimate, designers to scope flows, QA to write test cases, and stakeholders to check that what ships matches what was agreed.

A good PRD covers the what and the why. The how (architecture, data model, API shape) usually belongs in a separate technical design doc that engineering writes once the requirements are stable. Keeping the two apart keeps the PRD readable for non-engineers and stops implementation details from being mistaken for requirements.

Who writes the PRD?

The product manager usually owns the PRD: they draft it, keep it current and make the final call on scope. Owning it doesn’t mean writing it alone. Strong PRDs pull in an engineering lead early to flag feasibility and hidden cost, a designer to shape the user flows, and sometimes QA, support or data to sharpen edge cases and success metrics.

On teams without a dedicated PM, a tech lead, founder or engineering manager often writes it. What matters is that one person is accountable for the document and that the people who will build it have reviewed it before planning starts.

PRD template: the sections to include

Use this outline as a starting point and drop what doesn’t apply. A small feature may need only the first six sections.

• Overview: one paragraph on what is being built and why now.
• Problem and context: the user pain, the evidence for it (research, tickets, usage data) and what happens if you do nothing.
• Goals and success metrics: the outcomes you expect and how you will measure them.
• Non-goals: what is explicitly out of scope for this release.
• Users and use cases: who the feature serves and the main scenarios, often written as user stories.
• Requirements: numbered functional requirements, each with acceptance criteria and a priority (must, should, could).
• Non-functional requirements: performance, security, accessibility, privacy and localization.
• Design: links to mockups or prototypes and notes on the key flows.
• Dependencies and assumptions: other teams, services or decisions this relies on.
• Release plan: phases, milestones and the rollout or feature-flag approach.
• Open questions: unresolved decisions, each with an owner.
• Change log: what changed in the document and when.

How to write a PRD

Write the problem before the solution, and get feedback before you polish.

• Start with the problem statement and its evidence. If you can’t explain the problem in two or three sentences, you aren’t ready to write requirements.
• Define success metrics and non-goals next. Together they do more to prevent scope creep than any single requirement.
• Write requirements as numbered, testable statements. "An admin can export invoices as CSV" beats "export should be easy."
• Add acceptance criteria to each requirement so engineering and QA share one definition of working.
• Review the draft with engineering and design before calling it final, and log their questions under open questions.
• Break the approved requirements into epics and stories for the backlog, linking each back to the PRD.
• Keep it current. When a decision changes scope, update the PRD and note it in the change log.

PRD vs BRD vs FRD

The three documents answer different questions, and many teams merge them. If a software team writes only one, it is usually the PRD.

• BRD (business requirements document): why the business wants this. Objectives, expected value, stakeholders, constraints and budget. Often written by a business analyst or the project sponsor.
• PRD (product requirements document): what the product must do for its users to meet those objectives. Problems, use cases, requirements and success metrics. Usually owned by product.
• FRD (functional requirements document): exactly how the system should behave. Inputs, outputs, business rules, validations, error states and interfaces. Often written by a business or systems analyst, sometimes with engineering.
• In practice: large enterprises and regulated industries may use all three; most product teams use a PRD plus a technical design doc.

How to write a PRD for AI coding tools

AI coding assistants and agents can turn a clear PRD into working code, but they can’t catch you in the hallway to ask what you meant, so ambiguity turns into guesses. Write for a reader who is fast, literal and has no context beyond what you give it.

• State the tech stack, the existing patterns and files to follow, and anything the tool must not touch.
• Split the work into small requirements that can each be built and tested on their own.
• Write acceptance criteria as concrete checks, including edge cases and error states.
• Spell out non-goals so the tool doesn’t build extras you didn’t ask for.
• Include sample inputs and expected outputs, data shapes or API contracts where they exist.
• Ask the tool to restate its plan before it writes code, then review the diff against the PRD.